A game of base ball took place yesterday on the old "Jackson" grounds near Lafayette Park between the "Pickwick" B.B.C., of the St. Louis University, and the "Palmetto" B.B.C., of the Academy of the Christian Brothers. At the close of the seventh innings the game was called, and the "Pickwick" was pronounced victorious; the score being "Pickwick," 65 runs; "Palmetto," 20 runs.

-Missouri Republican, November 16, 1866

This is a very interesting reference to "the old 'Jackson' grounds." I have a nice list of 19th century, St. Louis baseball grounds and the Jackson grounds is not on it. Given the reference to the grounds being near Lafayette Park, I have to think that this is what would become known, in 1867, as the Veto Grounds and, later, the Compton Avenue grounds would be built on the site. Interestingly, I also have a reference to a Jackson Base Ball Club, in St. Louis, in 1865 and it is possible that the club used the site as their home grounds, although it's also possible that the name of the grounds came from the fact that it was located at the former site of Camp Jackson. The site was certainly being used as a baseball grounds that year, with the Defiance and Liberty clubs playing a match there on June 18, 1865. Also, the Empire Club used the site as their home grounds in 1866.

So I'm thinking that the Jackson grounds was located on the old Camp Jackson site (which was just south of SLU, making it convenient for a SLU/CBC game) and possibly was used by the Jackson Club in 1865. It would later become known as the Veto Grounds, be used as the Empire Club's home grounds and Thomas McNeary would build the Compton Avenue Grounds at the site in 1874. It's a site with a rich baseball history.